CVE-2021-44392 in RLC-410W
Summary
by MITRE • 01/29/2022
A denial of service vulnerability exists in the cgiserver.cgi JSON command parser functionality of reolink RLC-410W v3.0.0.136_20121102. A specially-crafted HTTP request can lead to a reboot. GetImage param is not object. An attacker can send an HTTP request to trigger this vulnerability.
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Analysis
by VulDB Data Team • 02/02/2022
This vulnerability resides within the cgiserver.cgi component of reolink RLC-410W firmware version 3.0.0.136_20121102, representing a critical denial of service flaw that can be exploited to remotely reboot the device. The issue manifests in the JSON command parser functionality where the system fails to properly validate input parameters, specifically the GetImage parameter which should be an object but is being processed as a non-object value. This improper handling creates a parsing error that ultimately results in system instability and forced device reboot.
The technical implementation of this vulnerability stems from inadequate input validation and parameter parsing within the web server component of the camera firmware. When an attacker crafts a malicious HTTP request containing a specially formatted GetImage parameter that violates expected object structure, the parser encounters a parsing failure that cascades into a system crash. This represents a classic example of improper input validation where the application does not adequately sanitize or verify the structure of incoming JSON data before processing. The vulnerability aligns with CWE-20, which addresses improper input validation, and specifically demonstrates weaknesses in data parsing and error handling mechanisms.
From an operational standpoint, this vulnerability presents significant risk to network security and availability. The ability to remotely trigger a device reboot without authentication creates opportunities for persistent disruption of surveillance operations, potentially leaving security gaps during the reboot period. Network administrators may experience service interruptions as the camera becomes temporarily unavailable, and in environments where continuous monitoring is critical, this could result in security breaches or compliance violations. The vulnerability is particularly concerning as it requires no authentication credentials to exploit, making it accessible to any attacker who can reach the device over the network.
The attack surface for this vulnerability extends across all network interfaces where the camera's web server is accessible, including both internal and external network segments if the device is exposed to the internet. Attackers can leverage this flaw through simple HTTP request manipulation, making exploitation straightforward and requiring minimal technical expertise. The impact extends beyond simple denial of service as it could be combined with other attack vectors to create more sophisticated compromise scenarios, potentially allowing attackers to establish persistent access or disrupt critical security infrastructure. Organizations should consider implementing network segmentation and access controls to limit exposure, while also ensuring firmware updates are applied promptly to address this vulnerability.
Mitigation strategies should include immediate firmware updates from reolink to address the parsing error and input validation weakness. Network administrators should implement firewall rules to restrict access to the camera's web interface to trusted networks only, and consider disabling unnecessary services or ports. Monitoring for suspicious HTTP requests and unusual reboot patterns can help detect exploitation attempts. The vulnerability demonstrates the importance of robust input validation in embedded systems and web applications, aligning with ATT&CK technique T1499.001 for network denial of service and highlighting the need for proper error handling in application code. Regular security assessments and penetration testing of networked devices should be conducted to identify similar parsing vulnerabilities in other embedded systems.